CPPLapack Code

//=============================================================================
/*! return transposed dgematrix */
inline _dsymatrix t(const dsymatrix& mat)
{
#ifdef  CPPL_VERBOSE
  std::cerr << "# [MARK] t(const dsymatrix&)" << std::endl;
#endif//CPPL_VERBOSE
  
#ifdef  CPPL_DEBUG
  std::cerr << "[WARNING] t(const dsymatrix&)" << std::endl
            << "This function call has no effect "
            << "since the matrix is symmetric." << std::endl;
#endif//CPPL_DEBUG
  
  dsymatrix newmat(mat);
  return _(newmat);
}

//=============================================================================
/*! return its inverse matrix */
inline _dsymatrix i(const dsymatrix& mat)
{
#ifdef  CPPL_VERBOSE
  std::cerr << "# [MARK] i(const dsymatrix&)" << std::endl;
#endif//CPPL_VERBOSE
  
  dsymatrix mat_cp(mat);
  dsymatrix mat_inv(mat.N);
  mat_inv.identity();
  
  char UPLO('L');
  long NRHS(mat.N), LDA(mat.N), *IPIV(new long[mat.N]), LDB(mat.N), LWORK(-1), INFO(1);
  double *WORK( new double[1] );
  dsysv_(UPLO, mat.N, NRHS, mat_cp.Array, LDA, IPIV, mat_inv.Array, LDB, WORK, LWORK, INFO);
  LWORK = long(WORK[0]);
  delete [] WORK;  WORK = new double[LWORK];
  dsysv_(UPLO, mat.N, NRHS, mat_cp.Array, LDA, IPIV, mat_inv.Array, LDB, WORK, LWORK, INFO);
  delete [] WORK; delete [] IPIV;
  if(INFO!=0){
    std::cerr << "[WARNING] i(dsymatrix&) Serious trouble happend. INFO = " << INFO << "." << std::endl;
  }
  
  return _(mat_inv);
}


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///////////////////////////////////////////////////////////////////////////////

//=============================================================================
/*! search the index of element having the largest absolute value
  in 0-based numbering system */
inline void idamax(long& i, long& j, const dsymatrix& mat)
{
#ifdef  CPPL_VERBOSE
  std::cerr << "# [MARK] idamax(long&, long&, const dsymatrix&)" << std::endl;
#endif//CPPL_VERBOSE
  
  i=j=0;
  double val(0.);
  for(long J=0; J<mat.N; J++){
    long I( J +idamax_(mat.M-J, mat.Darray[J]+J, 1) -1 );
    if( val<fabs(mat.Darray[J][I]) ){
      val =fabs(mat.Darray[J][I]);
      i=I;
      j=J;
    }
  }
}

//=============================================================================
/*! return its largest absolute value */
inline double damax(const dsymatrix& mat)
{
#ifdef  CPPL_VERBOSE
  std::cerr << "# [MARK] damax(const dsymatrix&)" << std::endl;
#endif//CPPL_VERBOSE
  
  long i,j;
  idamax(i, j, mat);
  return mat(i,j);
}